the top image is ftp sensor which was erratic and causing a code fault in ftp sensor,after checking the sensor,tightening connections to sensor,i noticed the ftp was so rapid on the scope it had to be electronic generated so i disconnected the alternator,all coils one at a time,checked powers and grounds for noise,started disconnecting sensors and switches and when i disconnected the p/s switch the concern went away.
the ps switch was cycling way faster the normal it is just a on off switch i am thinking because the cycling was so fast that it was confusing the pcm software and sending the signal down the ftp sensor circuit

What were the specifics of the vehicle?  year,make,model?

fordman wrote on Jun 29^th, 2013 at 8:02am:


Sorry for the beginner-type question, but may I ask what is the PS switch, and these other devices:vpwr,vref,sig rtn ?

Thanks for you help!

Partyzan wrote on Jan 30^th, 2014 at 10:48pm:


PS=power steering switch--this ends a signal to the PCM that slightly raises the RPM by opening the IAC (idle air control) further, to prevent stalling the engine, when doing parking type maneuvers.